Gefen Wireless for HDMI System Review - Home Theater Forum and Systems - HomeTheaterShack.com

 
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Gefen Wireless for HDMI System Review

Gefen Wireless for HDMI System

Can it be true? Has wireless HDMI finally arrived? For the past couple of years, manufacturers have teased us with demonstrations of wireless HD video transmission. Some of these demos even came with specific product release dates, but sadly, those dates always came and went with no products actually appearing on the retail shelf. I was beginning to give up hope on the wireless HD revolution, but it appears that 2009 is finally the year. Manufacturers like Sharp and Panasonic have introduced high-end TV models that incorporate wireless HD video transmission, and Sony's proprietary Bravia Wireless Link Module is available for Bravia HDTV owners.

What if you already own an HDTV (and it isn't a Sony)? Is wireless HDMI still an option? Thanks to Gefen, it is. The company has released not one but two standalone wireless HDMI systems: one for in-room applications and one for multiroom applications. Naturally, I jumped at the chance to see how well these new products deliver on the enticing promise of wireless HD.

The Hookup
A number of competing wireless HD transmission technologies are vying for the attention of manufacturers and consumers at this point, including 802.11n, UWB, WHDI and WirelessHD. What distinguishes them is the frequency band in which they operate and the type of compression they use or don't use, as the case may be. Gefen has opted to employ UWB, or ultra-wideband, for its in-room application and WHDI for its multi-room application. Both Gefen products support HD video resolutions up to 1080p/30, as well as compressed 5.1-channel audio soundtracks (Dolby Digital and DTS) and two-channel PCM up to 48kHz. The boxes include a sender unit that attaches to your sources, a receiver unit that attaches to your display device, power adapters and a single HDMI cable.

Wireless for HDMI UWB
The Wireless for HDMI UWB system (EXT-WHDMI, $999) uses a UWB platform developed by Tzero Technologies. Ultra-wideband is an RF technology that (as the name suggests) sends bursts of information over a wider frequency range, so it's less susceptible to interference. The Gefen product operates in the 3.1- to 4.8-GHz range and uses a compression technology called JPEG2000, which Gefen says offers a throughput of 65 Mbps. UWB is ideally suited for line-of-sight, short-range communication, around 30 feet, which is why this product is best used as an in-room solution. In my case, I sent the signal from an equipment rack located in the back of the room to a Samsung HDTV located in the front of the room, about 13 feet away.

Physical set-up is quite simple, requiring nary a peek at the owner's manual. The sender and receiver units are horizontally aligned boxes, about half the length of the average source component, with antennas sprouting from the top. The sender unit has two HDMI 1.2a inputs and one component video input, along with a stereo analog audio input, to accommodate a total of three high-def sources; the receiver unit has a single HDMI 1.2a output, plus a stereo analog audio output, for connection to your display device. I fed HDMI from my DirecTV HD DVR and Pioneer Blu-ray player directly into the sender unit. The sender unit's Select button allows you to switch between the three inputs, with blue LEDs that indicate which source you've selected. The package doesn't include a remote control to switch inputs; however, you can enable an Auto function that detects the first connected HDMI source and switches to a new HDMI source when you power it up.

If you need to connect more HD sources and/or want to remotely control the switching function, the better hookup option is to simply feed the HDMI output from an A/V receiver or external video processor into one of the sender unit's HDMI inputs and let that device handle the switching duties. I tried this approach using a DVDO scaler, and it worked fine. The UWB product incorporates an IR repeater system. The receiver unit can send IR commands from your remote back to the sender unit, which has an IR blaster port to connect to your gear.

The sender and receiver units sport LEDs for Link and Video, both of which should glow a steady blue when the handshake is established and video is transmitting properly. Happily, this is exactly what I got when I powered everything up.

Wireless for HDMI 5GHz
The Wireless for HDMI 5GHz system (GTW-WHDMI, $899) is designed to travel over a longer distance (up to 100 feet) and work more reliably through walls and other obstructions. The 5GHz model (it actually works over the 5.1- to 5.8-GHz band) is based on WHDI, a technology created by Amimon that allows for the transmission of uncompressed HD signals. The vertically-oriented sender and receiver units resemble modems and come with simple snap-on bases. The front panels contain just two LEDs: one for power and one for link. The latter flashes quickly when there's no link, flashes slowly when the handshake between sender and receiver is established, and glows solid blue when the A/V signal is transmitting properly. In terms of connections, the sender unit has just a single HDMI 1.2 input, while the receiver unit has one HDMI 1.2 output, plus a stereo analog audio output, to connect to your displace device. As with the UWB model, I experimented with direct connection of each source to the sender unit and also tried attaching the DVDO scaler to switch between multiple sources; I sent the signal wirelessly to a TV located on the second level of the house, with about 25 feet from source to display through the floor. Once again, after I connected everything and powered it up, the A/V signal appeared on the remote TV with no issues.

The 5GHz model has two modes, Unicast and Broadcast. The default Unicast mode lets you use only one receiver per sender; the Broadcast mode will send the signal to five receivers, but does not support HCDP material.

Performance
When it comes to performance, the two key issues for any wireless HDMI product are signal reliability and video quality. In both of these areas, the Gefen products prove themselves up to the task. In regards to signal reliability, the 5GHz model never dropped the signal or exhibited even a minor interference hiccup. You'd never guess that the HD signal was being transmitted wirelessly from another room. I was most curious to see how the in-room model would perform, since UWB is more prone to interference if there are too many obstructions between the sender and receiver. Gefen recommends you place the sender unit at a height of at least five feet for optimal performance (the receiver unit's height does not matter), and indeed at this height I encountered no signal drop-outs, even when I parked myself directly between the sender and receiver antennas and tried to cause a disruption. Next I tried lowering both products to the floor, and still the link remained intact. I also tried moving the sender unit into the next room at about the maximum recommended distance of 30 feet, with one wall boundary in between, and the two devices still communicated just fine. Only when I moved the sender even further away and added a second wall boundary did the link finally break. So, even though Gefen recommends line-of-sight, the UWB system is stable enough to accommodate some obstructions.

As for picture quality, I saw no blatant degradation with either system. These are pass-through devices only, so no scaling or deinterlacing is involved. Resolution test patterns revealed no meaningful loss of detail with either unit; the finest lines in the resolution patterns were perhaps a shade dimmer with the Wireless for HDMI products in the chain, but it was nothing significant. Real-world HDTV (720p and 1080i) and Blu-ray (1080p/24) content had excellent detail, and there were no dropped frames to lead to choppy motion. Fine black details were still evident in demo scenes from The Pirates of the Caribbean: The Curse of the Black Pearl Blu-ray disc (Buena Vista Home Entertainment) and The Bourne Supremacy DVD (Universal Studios Home Video). The only minor issue I noticed was with the UWB model, which does use compression. In the opening of chapter 17 from the Kingdom of Heaven Blu-ray disc (Twentieth Century Fox Home Entertainment), I saw a slight banding, or uneven transition, from light to dark blue in the sky, which was not evident with a hardwired HDMI connection. This suggests a lack of bit depth. I did not see the same issue with 5GHz sample, which uses an uncompressed transmission method.

Beyond the main performance parameters, the primary reason to adopt a wireless system is convenience, and these products are certainly convenient. As I said, they're very easy to set up and it takes just seconds to move them around the house to accommodate different A/V gear. I successfully used both models with lots of different components; I even added a distribution amplifier and used both models simultaneously to wirelessly transmit the signal to multiple displays. As an example of just one set-up, I own a single DirecTV HD DVR, located downstairs in my theater room. In the upstairs rooms, I use basic HD satellite receivers. The 5GHz multi-room model allowed me to watch recorded content from the downstairs box in any other room in the house just by moving the receiver unit and using my RF universal remote. Similar functionality in the wired world would require running cable through walls all over the house.

The UWB model, meanwhile, is a good solution for those who want to mount their flat panel on a wall away from the equipment rack or for those who want to ceiling-mount a projector without having to run video cables through the walls. Once again, there's a freedom to move things around that you just don't get with wired solutions.

Low Points
The biggest drawback to both the UWB and 5GHz models - one that could very well be a deal-breaker for many - is that neither unit supports a 1080p/60 resolution. They support 1080p/24, which suits them for most new Blu-ray players, but the inability to pass 1080p/60 is problematic for people who own early-generation HDMI products. If your Blu-ray player lacks 1080p/24 output or your TV won't accept 1080p/24 input (which is very common with older HDMI sets), then you're forced to set your player to output 1080i instead. Most 1080p-capable upconverting DVD players don't output 1080p/24, nor do cable/satellite set-top boxes. The latter may not matter as much now, but it may become more of an issue as cable and satellite providers offer more 1080p video-on-demand content. Given the price premium that these wireless products demand, the fact that they can't support the same resolutions as their wired counterparts is less than ideal. It's worth noting that this is a technology issue, not a Gefen issue. Competing standalone products, which have not yet hit the market, don't support 1080p/60 either. Also, Gefen has announced plans for the July/August release of a 1080p/60-capable wireless HDMI solution based on WirelessHD technology; WirelessHD works in the 60GHz band and can send uncompressed 1080p/60 up to 30 feet.

Even if you do own a 1080p/24-capable Blu-ray player, you need to make sure it's set up correctly, or it might confuse the Gefen products and lead to "invalid format" messages and handshake errors, which was the case with one Panasonic player I used. Go with the Auto resolution setting (as opposed to a locked 1080p setting) and, of course, make sure to enable 24p playback.

The Gefen products also don't support the transmission of uncompressed multichannel PCM audio, like decoded Dolby TrueHD or DTS-HD soundtracks from a Blu-ray player. This is less of a concern in my book. It's really only an issue if the destination of your wireless signal is not a TV or projector. Most TVs have a two-channel (and usually sub-par) audio system anyhow. However, if for some reason you wanted to send the signal wirelessly from a remote Blu-ray player to your A/V receiver, then you'd have to sacrifice the higher-quality audio experience.

Both products are somewhat slow to switch between resolutions, which is more of an issue with a satellite/cable box than it is with a disc player. You can remedy this by configuring your set-top box to output a single resolution (some set-top boxes only let you output a single resolution) or by feeding all of your sources into a receiver or video processor that outputs a single resolution. Also, the Auto switching function on the UWB model doesn't work reliably, especially if one of your sources is an always-on HD DVR.

Finally, all of those bright, blue LEDS on the UWB sender and receiver units can be pretty distracting in a dark or even a moderately-lit room, so you'll want to make sure to hide the units as best you can. The UWB units also have an audible hum that's quite noticeable in a silent room and may distract during quiet scenes, so be mindful of how close you place them to the listening area.

Conclusion
The wireless HD revolution has arrived, and Gefen deserves props for helping to usher it in with two standalone product solutions, both of which have convenience, reliability and good performance on their side. As with any hot new technology, though, the price of being an early adopter is fairly steep. The 5GHz model's $899 asking price makes sense, as you could easily spend that much to run cables through your walls to remote locations and still not have the flexibility you get here. Additionally, the 5GHz model costs several hundred dollars less than the competing Belkin multi-room unit that has yet to arrive on the market. However, the $999 asking price for the UWB model is harder to justify, compared with a 30-foot HDMI cable. Even when you factor in the three-source HD switching and IR repeater functions, it's still a pricey in-room solution. If you don't need the switching and IR features, it makes more sense to get the 5GHz model and use it as an in-room solution: it costs $100 less, it's quieter with fewer distracting LEDs, and it offers slightly better video performance. Otherwise, you might want to wait and check out the WirelessHD model, which will do 1080p/60.

For those of you who simply can't abide the sight of A/V cables and are unwilling or unable to run wires through your walls, the good news is that there's finally an easy, high-performing wireless HDMI solution. But, until the technology trickles down to the mainstream, be prepared to pay for it.

Chrisy

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5ghz , amimon , gefen , hdmi , jpeg2000 , tzero , ultra-wideband , whdi , wireless , wirelesshd

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